In visible light communication systems, data signals are modulated into visible light. At practical data rates, the modulation is too rapid to be sensed by the human eye. The visible light can thus be used for both illumination and communication. Light emitting diodes (LEDs) are often used as the light source because, amongst other things, their output can be modulated sufficiently rapidly.
The use of white LEDs for illumination is also becoming increasingly widespread.
US 2011/0069958 A1 discloses an aircraft data communication system using optical wireless data transmission. The light is non-coherent infrared light.
A communication apparatus for forwarding a mobile telephony signal to a mobile device and a communication system using light are subject of WO 2013/114103 A1. US 2012/0134433 A1 and US 2012/0044846 A1 are related to communication systems allowing efficient transmission and energy reduction.
Nevertheless, many ways of exploiting the potential of visible light communications and of implementing practical systems remain unexplored.
DE 20 2013 006 570 U1 describes a surgical lamp wherein LEDs are used and the colour temperature of the emitted radiation can be varied between 3.500 and 5.500 K. As well, the radiation intensity can be varied.
Another conventional surgical LED lamp is shown in FIG. 1.
DE 10 2008 012 824 A1 describes a further surgical lamp comprising a signal light source emitting light that may be modulated so that it includes information for transmission to the surgical area and to a surgical instrument. The surgical instrument, on the other hand, may be equipped with means for transmitting information such as measurement values to the surgical lamp.
Use of WLAN and WiFi in the field of medicine involves problems with respect to security. These include disturbances because of frequencies overlapping with those of other equipment that may result in undesired signal/noise ratios up to cutting the connections. Apart therefrom other problems are caused by the requirement of fast data transmission not being met by WLAN and WiFi networks. Further the security of the signals and the possibility of WiFi and WLAN penetrating the walls and the signal being available outside of the operation room, or of signals entering the operation room from outside of the operation room are unacceptable risks.
Further there are many risks introduced into the operation room setting with the encumbrance of cables and multiple cables per operation room device in the room. Cables pose both a physical risk to the patient and to the medical personnel who must carefully work around them. They impede movement and ease of function as well as act as vectors for transmitting infection and disease. It is very difficult to sterilize cables and connectors. It is very easy to trip over them.